## Search found 156 matches

- Sat Jul 10, 2010 10:48 am UTC
- Forum: Mathematics
- Topic: Math: Fleeting Thoughts
- Replies:
**434** - Views:
**152328**

### Re: Math: Fleeting Thoughts

It hasn't been said yet, but I hate it when people say "timesing" or "minusing" instead of "multiplying" or "subtracting". But it's overly ridiculous when people say "plussing" instead of "adding". It makes me want to scream. Although I ha...

- Sat May 29, 2010 5:50 am UTC
- Forum: Mathematics
- Topic: Math discovered or invented?
- Replies:
**110** - Views:
**17583**

### Re: Math discovered or invented?

Except that triangles don't exist in the real world, they're merely simplifications of nature we're capable of articulating. Mathematical objects are in general defined , their dependency on language should be obvious from that alone. I'd say that mathematical objects are more like unicorns, they b...

- Fri Mar 26, 2010 6:07 am UTC
- Forum: Logic Puzzles
- Topic: My Hobby: Simplifying Sentences
- Replies:
**16** - Views:
**7599**

### Re: My Hobby: Simplifying Sentences

Are the spaces placed randomly? if they are, the possibilities are too many... As far as I understand, word order, spaces and punctuation are preserved. But ignoring this, they are still solvable. Since the first-of-each-letter order is preserved, they are always easier than anagrams, which are sti...

- Mon Mar 22, 2010 6:58 am UTC
- Forum: Mathematics
- Topic: So, my dad sent me 30 dollars
- Replies:
**17** - Views:
**3069**

### Re: So, my dad sent me 30 dollars

God Created the Integers: The Mathematical Breakthroughs That Changed History by Stephen Hawking is perhaps the thickest and densest book within your budget. Pros: Lots of math. Definitely does NOT follow the "for every math formula, half the sales..." philosophy. This book is not trying ...

- Mon Mar 22, 2010 6:04 am UTC
- Forum: Logic Puzzles
- Topic: Bear Puzzle
- Replies:
**23** - Views:
**16890**

### Re: Bear Puzzle

My thought (which didn't go anywhere): Newtonian mechanics tells us what the bear's acceleration was (assuming no initial velocity, and constant acceleration): \begin{eqnarray*}d &=& \frac{a}{2}t^2\\ -19.617\:\textrm{m} &=& \frac{a}{2}(2\:\textrm{s})^2\\ a &=...

- Sat Mar 20, 2010 7:50 am UTC
- Forum: Logic Puzzles
- Topic: Bear Puzzle
- Replies:
**23** - Views:
**16890**

### Re: Bear Puzzle

My thought (which didn't go anywhere): Newtonian mechanics tells us what the bear's acceleration was (assuming no initial velocity, and constant acceleration): \begin{eqnarray*}d &=& \frac{a}{2}t^2\\ -19.617\:\textrm{m} &=& \frac{a}{2}(2\:\textrm{s})^2\\ a &=&...

- Thu Mar 18, 2010 5:41 am UTC
- Forum: Mathematics
- Topic: Happy Pi Day!
- Replies:
**12** - Views:
**1741**

### Re: Happy Pi Day!

BlackSails wrote:My favorite approximation to pi:

3! (thats an exclamation point, not a factorial)

No, 4 is a better approximation.

... for very square circles.

- Wed Mar 17, 2010 6:37 am UTC
- Forum: Mathematics
- Topic: Prime modulo prime triangle
- Replies:
**1** - Views:
**469**

### Prime modulo prime triangle

I couldn't find this anywhere else, so here it goes. Please excuse my possibly strange terminology. I do lots of math without any formal instruction, so I don't always know the correct terminology. First of all, I'm using P(n) to mean the nth prime, where P(0)=2. The entry at row m and column n is P...

- Sun Mar 14, 2010 9:56 pm UTC
- Forum: Mathematics
- Topic: Happy Pi Day!
- Replies:
**12** - Views:
**1741**

### Re: Happy Pi Day!

Here's one of my favorite definitions of pi, as it's very easy to compute (though probabilistic):

[math]\frac{\pi}{4}=P(x^{2}+y^{2}\le1)[/math] where x and y are randomly chosen points in the unit interval.

[math]\frac{\pi}{4}=P(x^{2}+y^{2}\le1)[/math] where x and y are randomly chosen points in the unit interval.

- Wed Mar 10, 2010 2:01 am UTC
- Forum: Science
- Topic: Are all universes Turing-complete?
- Replies:
**20** - Views:
**2516**

### Are all universes Turing-complete?

Following the analogy that the universe is essentially an automaton, it can easily be shown that we live in a Turing-complete universe, because we are able to implement Turing-complete systems within its rules. My question is, must all universes in the multiverse (ones with twerked fundamental const...

- Wed Feb 24, 2010 2:20 am UTC
- Forum: Mathematics
- Topic: An interesting numeral system
- Replies:
**28** - Views:
**7102**

### Re: An interesting numeral system

Here's a way to solve the problem/redundancy of every number except for zero starting with a 1. Here f is the function that encodes a number as a string, and + is string concatenation: f(n)=\begin{cases} \textrm{"0"} & n=0\\ \textrm{"1"} & n=1\\ \textrm{"[&qu...

- Wed Feb 17, 2010 9:21 am UTC
- Forum: Coding
- Topic: Coding: Fleeting Thoughts
- Replies:
**9979** - Views:
**1979645**

### Re: Coding: Fleeting Thoughts

Today in french class, we were given some Mardi gras vocabulary, and to my humor, I saw that the french word "char" means "float". Of course, it means a carnival float and not a floating-point number, but I thought it was neat nonetheless. And I was the only person in the room wh...

- Wed Feb 17, 2010 9:08 am UTC
- Forum: Mathematics
- Topic: Significant Figures
- Replies:
**9** - Views:
**1756**

### Re: Significant Figures

I give the answers in the most exact form I can. However, in IB math, you must give either exact answers, or inexact answers to three significant figures. Significant figure "rules" only apply in operations with measurements whose precisions are not explicitly given, as a rough way of pres...

- Tue Feb 16, 2010 9:13 am UTC
- Forum: Mathematics
- Topic: An interesting numeral system
- Replies:
**28** - Views:
**7102**

### Re: An interesting numeral system

jestingrabbit wrote:afarnen wrote:* This uses only three symbols,

for large values of three.

Yeah, I guess I meant five.

- Tue Feb 16, 2010 7:17 am UTC
- Forum: Serious Business
- Topic: December 21st 2012
- Replies:
**77** - Views:
**12031**

### Re: December 21st 2012

Voice of reason wrote:And I don't think it will be the appocalpse I think it will begining of the end or the halfway point.

Oh, okay. It's one of those compromise theories.

From comic 690: "I believe the truth always lies halfway between the most extreme claims."

- Tue Feb 16, 2010 3:09 am UTC
- Forum: Mathematics
- Topic: An interesting numeral system
- Replies:
**28** - Views:
**7102**

### Re: An interesting numeral system

http://en.wikipedia.org/wiki/Mixed_radix#Primorial_based_radix This is sometimes known as the "Primoradic" numbering system. Thanks for the link. Yes, they're similar in appearance... as they are both numeral systems, and both refer to the prime numbers, but they are fundamentally complet...

- Tue Feb 16, 2010 1:33 am UTC
- Forum: Mathematics
- Topic: An interesting numeral system
- Replies:
**28** - Views:
**7102**

### An interesting numeral system

The other day I discovered a neat notation for uniquely representing numbers (I'm not sure what numbers... at least all rational numbers). I have searched, but have not come across such a notation--if something at least similar exists, please point it out. Its basis is the fundamental theorem of ari...

- Thu Feb 11, 2010 3:02 pm UTC
- Forum: Religious Wars
- Topic: The Turing Machine vs. Lambda Calculus
- Replies:
**32** - Views:
**21288**

### Re: The Turing Machine vs. Lambda Calculus

My vote is with the Lambda Calculus. First of all, I just find this to be pretty: (\lambda mnfx.mf(nfx))(\lambda fx.f(f(fx)))\lambda fx.(f(f(f(f(fx))))) Second, the entire state of, and everything you need to know about ...

- Tue Jan 12, 2010 11:06 pm UTC
- Forum: Logic Puzzles
- Topic: A kind of "The Lady or the tiger" puzzle machine.
- Replies:
**63** - Views:
**13397**

### Re: A kind of "The Lady or the tiger" puzzle machine.

This is really fun! I like the idea of the wizards, humans and vampires. I have two questions. If a liar said, for example, "At least one human is telling the truth," does this guarantee the existence of a human? Does "All the humans are lying" guarantee the existence of at least...

- Wed Jan 06, 2010 5:25 am UTC
- Forum: Coding
- Topic: Coding: Fleeting Thoughts
- Replies:
**9979** - Views:
**1979645**

### Re: Coding: Fleeting Thoughts

python does it too, of course.... Anyway, customizable syntax is great until you want to collaborate in any way, or use someone else's code from the web. True. It seems like more of a gimmick than useful. It'd be difficult to standardize. However, some sort of language-independent preprocessor coul...

- Tue Jan 05, 2010 9:12 pm UTC
- Forum: Coding
- Topic: Coding: Fleeting Thoughts
- Replies:
**9979** - Views:
**1979645**

### Re: Coding: Fleeting Thoughts

I've been wishing recently that there was a language with an easily customizable syntax. Like, if you could change the name of keywords. Or change the position (infix/prefix/postfix), precedence or associativity of operators, or the code-blocking style (curly-brackets vs. python-style), etc. That w...

- Tue Jan 05, 2010 1:56 pm UTC
- Forum: School
- Topic: ACT scores
- Replies:
**81** - Views:
**10797**

### Re: ACT scores

I took it once without really knowing what I was getting into--that science section was a surprise. And I didn't get much sleep (excuses, excuses).

Well, I'm happy about 35 in math and 33 in english. Not so happy about my (identical) reading and science scores which made my composite a 30.

Well, I'm happy about 35 in math and 33 in english. Not so happy about my (identical) reading and science scores which made my composite a 30.

- Tue Jan 05, 2010 12:28 pm UTC
- Forum: Coding
- Topic: Coding: Fleeting Thoughts
- Replies:
**9979** - Views:
**1979645**

### Re: Coding: Fleeting Thoughts

I've come up with a minimally "typed" variant of combinatory logic/programming language. It's very inspired by Haskell, ML and Miranda but it aims to be much more minimal. First of all, types are defined by 'constructors', which are like functions that never reduce or evaluate (by default)...

- Thu Dec 10, 2009 7:55 pm UTC
- Forum: Mathematics
- Topic: Why is standard deviation the root mean square? (merged)
- Replies:
**17** - Views:
**10963**

### Re: Why is standard deviation the root mean square? (merged)

Wow, I didn't expect to get so many replies. Thanks, I understand better now. One thing, I forgot that absolute value also applies to higher dimensions when I first read the "mean absolute deviation is complicated" argument, and was thinking "what's so hard about dropping a negative s...

- Wed Dec 09, 2009 10:24 pm UTC
- Forum: Mathematics
- Topic: Why is standard deviation the root mean square? (merged)
- Replies:
**17** - Views:
**10963**

### Standard deviation is awful

Today in math class, I looked at the arbitrary definition of standard deviation, and (not for the first time during a stats lesson) thought, why ? So I tried making sense of it, and eventually came up with a seemingly much better formula (called the mean deviation, which I didn't know at the time) w...

- Sat Dec 05, 2009 8:44 pm UTC
- Forum: Computer Science
- Topic: Discrete Structures
- Replies:
**12** - Views:
**3187**

### Re: Discrete Structures

If anybody needs an example of something taught in a discrete structures class, I visited one the other day, and the lesson was public-key cryptography, which included proving how RSA works, in detail, citing group theory, complexity theory, etc.

- Sun Nov 22, 2009 11:48 am UTC
- Forum: Coding
- Topic: B is cool!
- Replies:
**3** - Views:
**974**

### Re: B is cool!

Hmm.. B is a bit more interesting than I first thought.. Couldn't really image doing any "real" programming in it even as hobby work.. Right. I think it would have to be able to communicate with C libraries to do useful things (it can communicate with a Unix environment, however). Since t...

- Sat Nov 21, 2009 8:29 pm UTC
- Forum: Coding
- Topic: B is cool!
- Replies:
**3** - Views:
**974**

### B is cool!

I'd always heard of B (being the predecessor to C) and had seen its Hello World program: main( ) { extrn a, b, c; putchar(a); putchar(b); putchar(c); putchar('!*n'); } a 'hell'; b 'o, w'; c 'orld'; which would turn anybody off, right? That whole splitting up the string thing... However, this is perf...

- Sun Sep 27, 2009 1:27 am UTC
- Forum: Coding
- Topic: Fake Programming Language
- Replies:
**210** - Views:
**31104**

### Re: Fake Programming Language

You, sir, name? wrote:Congratulations. You have invented the abbacus.

Yes, my method of addition of peano numbers is similar, but this language can do so many other things, things that your abacus could only dream of doing . For instance, I bet I could write a lambda calculus interpreter.

- Sat Sep 26, 2009 11:56 pm UTC
- Forum: Coding
- Topic: Fake Programming Language
- Replies:
**210** - Views:
**31104**

### Re: Fake Programming Language

There's this simple language for which I've had the general idea in my mind for maybe a year. Anyway, it's a data-structured language, though I'm not sure if I want it to be string-based (e.g. a program could look like '2+2') or list-of-strings-based (e.g. a program could look like '2 plus 2', repre...

- Tue Sep 22, 2009 9:05 pm UTC
- Forum: Computer Science
- Topic: Making a 3D model from images
- Replies:
**4** - Views:
**1558**

### Re: Making a 3D model from images

The easiest way to do this would be to use pixel-perfect, bitmap stereogram (as computers aren't good at recognizing visual patterns, only patterns in bits). This would be done by taking two bitmap images (representing the left and right parts of a stereogram), and returning a single grayscale bitma...

- Fri Sep 18, 2009 4:41 am UTC
- Forum: Serious Business
- Topic: Instance of consciousness: A series of thought experiments
- Replies:
**65** - Views:
**10074**

### Re: Instance of consciousness: A series of thought experiments

First of all, I'm assuming that by the atoms in the person's body when disassembling/reassembling them you mean all particles, including atoms, free electrons, and photons, etc. And that you mean not only position, but momentum of these particles as well. In other words, the complete physical config...

- Fri Sep 18, 2009 3:21 am UTC
- Forum: Serious Business
- Topic: God is... or ____ is
- Replies:
**115** - Views:
**13496**

### Re: God is... or ____ is

God is unfalsifiable. God as an explanation for phenomena does not actually explain anything, nor can be disproved. (Self-proclaimed) theist: God makes the rain. (Self-proclaimed) atheist: No, the water cycle makes the rain. Theist: That's how God makes the rain. God is intuitive. Intuition leads u...

- Wed Jun 17, 2009 1:06 am UTC
- Forum: Logic Puzzles
- Topic: The Absent-Minded Miner
- Replies:
**38** - Views:
**4764**

### Re: The Absent-Minded Miner

I'm assuming that by orientation you mean his upside-down-ness, and not his compass direction in addition to this (his full 3D direction)? If the latter, then I don't think it should be assumed that he can either stay in the same direction all the time or that he always knows what direction he's in....

- Tue Jun 16, 2009 9:36 pm UTC
- Forum: Logic Puzzles
- Topic: The Absent-Minded Miner
- Replies:
**38** - Views:
**4764**

### Re: The Absent-Minded Miner

Suppose each chamber is a circle, with its shaft entrances on its circumference. When a miner walks into a chamber, he has to know which exit to take. In this example, he uses rotation about his own up-to-down axis. Now suppose the shafts are reminiscent of the twisting hallways from the Ocarina of...

- Wed Jun 10, 2009 7:42 pm UTC
- Forum: Logic Puzzles
- Topic: The Chicken or the Egg?
- Replies:
**41** - Views:
**5122**

### Re: The Chicken or the Egg?

I heard a joke on this subject: A chicken and an egg are lying in bed together. They've just finished the most mind-blowingly-awesome sex they've ever had. The chicken, with a cigarette in its beak, turns to the egg, smiles, and says "well, I guess we answered THAT question!" And so [/thr...

- Tue Jun 09, 2009 8:34 pm UTC
- Forum: Logic Puzzles
- Topic: The Sierpinski walk
- Replies:
**53** - Views:
**10868**

### Re: The Sierpinski walk

There is no iteration where (1/3,1/3) is removed, therefore the carpet (the limit of those iterations, or really the intersection of all those iterations) will still contain that point. So that mean only points which are on the edges of square holes are actually on the carpet? Otherwise it can be r...

- Tue Jun 09, 2009 7:32 am UTC
- Forum: Logic Puzzles
- Topic: The Sierpinski walk
- Replies:
**53** - Views:
**10868**

### Re: The Sierpinski walk

I'm confused as to how you can define a point on the Sierpinski carpet, when there are actually no points on it. What I mean is with enough iterations of the fractal, any chosen point can be proven to be not on the Sierpinski carpet, so if you're considering the fractal iterated ad infinitum, there ...

- Sat Jun 06, 2009 4:42 pm UTC
- Forum: Science
- Topic: Miscellaneous Science Questions
- Replies:
**2958** - Views:
**711554**

### Re: RELATIVITY QUESTIONS! (and other common queries)

This is not exactly a question, but more like a confirmation of an understanding of mine about general relativity. It's a bit more mathematical than scientific. The surface of a sphere is in a two-dimensional curved space (if you live on a sphere, you can move north, south, east, and west). However,...

- Thu May 28, 2009 3:30 pm UTC
- Forum: Computer Science
- Topic: Thoughts on P = NP
- Replies:
**32** - Views:
**7838**

### Re: Thoughts on P = NP

Honestly, this is why we should never have named it NP in the first place. Between the general public thinking it means Not Polynomial (for a restricted definition of general public), and then all this business about nondeterminism. Bah! Henceforth, NP is the class of problems which have an efficie...